This invention relates generally to cutting flat soft goods and more particularly, to feeding and cutting a stack comprised of different layers of soft goods. The invention is particularly useful for trimming the longitudinal edges of mattress covers and other quilted soft goods in large-scale, wide-width quilt manufacturer.
In the manufacture of bedding and furniture, a mattress cover or other cushion is often fabricated from layers of different soft goods. Such mattress covers are typically made on wide-width multi-needle quilting machines and associated panel cutters such as those described in U.S. Pat. Nos. 5,154,130, 5,544,599 and 6,237,517, all hereby expressly incorporated by reference herein.
For example, a mattress cover is often comprised of a stack of layers of different soft goods, which are often quilted together, that include a first, top layer of fabric ticking material, a second layer of a fiber material, a third layer of foam and a bottom layer of fabric backing material. Such a stack of compressible soft goods is about 2-6 inches thick and has a length and width corresponding to the size of the mattress cover being made. As part of the manufacturing process, it is necessary that the edges of the stack of soft goods be trimmed, so that the edges are straight and parallel. Known edge cutting machines have a motor-driven conveyor belt that transfers the stack of soft goods past a motor-driven compression roller and a pair of motor-driven cutting wheels. The compression roller compresses the stack of soft goods to a thickness of less than about three inches. A motor-driven cutting wheel is located on each side of the machine, and the cutting wheels must have a radius greater than the thickness of the compressed stack of soft goods, that is, at least about three inches.
While such a cutting operation is effective, it does have some disadvantages. First, the cutting wheel is relatively thin and has a tendency to bend or warp slightly from the cutting forces applied by the compressed stack of soft goods being moved past the cutting wheel by the conveyor. Thus, the cutting wheel has a tendency to drift or walk with respect to a desired straight cutting path, thereby producing a cut edge of the stack of soft goods that is rough and not straight over the length of the stack.
Second, the cutting wheel edge dulls with use and must be periodically sharpened. Therefore, a separate sharpening device is mounted adjacent the cutting wheel. In order to effect a sharpening cycle, the edge cutting operation is interrupted; and the sharpening device is manually or automatically moved into contact with the cutting wheel to execute a cutting wheel sharpening cycle. During the sharpening cycle, the cutting machine is out of production; and thus, the sharpening cycle reduces the efficiency of the machine operation and adds to the overall cost of the cutting operation.
In addition, the overall structure of the cutting machine is relatively complicated and costly. The cutting machine requires a motor-driven compression roller as well as a relatively wide motor-driven conveyor belt that provides a subjacent support for the stack of soft goods and moves it past the cutting wheel. A sharpener is also required, which has actuators that move the sharpener into contact with the cutting wheel; and often, a separate clamp is used. Such a system has different motors or actuators for powering the cutting wheel, the compression roller, the conveyor and for positioning the cutting wheel sharpener. Further, the operation of those actuators is often coordinated by a separate control. Such a complex cutting machine is expensive to build, operate and maintain; and that expense must be borne by the product, for example, the mattress cover, being trimmed on the cutting machine. This is particularly relevant to quilt manufacture.
Therefore, there is a need for a cutting machine that reliably provides a clean and straight cut edge over the full length of the stack of soft goods and that has a simpler and less costly structure. This need especially exists in the manufacture of quilts such as quilted mattress covers, that are manufactured on a large-scale.
The present invention provides a relatively compact and inexpensive slitter and feed mechanism that reliably feeds, compresses and cuts side edges of a quilt or other stack of soft goods.
According to certain embodiments of the invention, the slitter and feed mechanism achieves the feeding, compression and cutting actions with just a single motor. The use of only one motor represents a substantial cost savings over known feeding, compressing and cutting devices. A quilting panel cutter equipped with such a slitter and feed mechanism improves the quality and economy of the quilt making process.
According to other aspects of the invention, the slitter and feed mechanism further permits the compression force to be easily adjusted. The cutting edges of the slitting wheels are preloaded to more reliably hold the cutting edges in contact, so that a clean and consistent cutting action is provided. As a result, in a quilt manufacturing operation, quilts of differing thicknesses can be trimmed without the need for prolonged shutdown and adjustment of the quilting line.
In addition, with the slitter and feed mechanism of the present invention, the slitting wheels are mounted to be self-sharpening during use, thereby providing a more reliable cutting action over an extended period of time. Thus, the slitting process is more efficient because the machine does not have to be taken out of production to sharpen the slitting wheels. The slitter and feed mechanism of the present invention is especially useful in the textile industry for trimming a quilt or other stack of soft goods as is found, for example, in a cushion or mattress cover.
According to the principles of the present invention and in accordance with the described embodiments, the invention provides an apparatus for feeding and slitting soft goods such as a mattress cover or other quilt being supported on a table. The apparatus has a motor mounted on a frame and a first slitting wheel rotatable by the motor. A second slitting wheel is rotatable by the motor and contacts the first slitting wheel to provide a cutting action. Thus, both of the slitting wheels are rotatable by a single motor.
In one aspect of this invention, the apparatus further includes a conveying apparatus for conveying the soft goods past the slitting wheels; and the conveying apparatus is operably connected to the motor. Thus, the single motor not only operates the slitting wheels but also operates the conveying apparatus.
In another embodiment of the invention, an apparatus for slitting and feeding soft goods includes first and second slitting wheels that are rotatable by a motor. A biasing apparatus is mechanically connected to the first slitting wheel and biases the first slitting wheel against the second slitting wheel with a desired biasing force. Such a biasing forces maintains the first and second slitting wheels in contact during a cutting operation.
In a further embodiment of the invention, an apparatus for slitting and feeding soft goods includes first and second slitting wheels that are rotatable by a motor about respective first and second axes of rotation. The second axis of rotation is oblique to the first axis of rotation by an amount that results in a self-sharpening of the slitting wheels. In one aspect of the invention, the oblique axes of motion form an acute angle therebetween of about 2xc2x0. The oblique axes of rotation plus the slitting wheel biasing force provides a self-sharpening capability that substantially improves the durability, quality and reliability of the cutting action of the slitting wheels.
In yet another embodiment of the invention, an apparatus for slitting and feeding soft goods includes first and second slitting wheels that are rotatable by a motor. A powered lower conveyor contacts and supports a lower surface along an edge of the soft goods; and a powered upper conveyor contacts an upper surface along the edge of the soft goods. The upper conveyor has an upper conveyor belt with a belt portion resiliently movable in a generally vertical direction with respect to the lower conveyor. The upper conveyor is thus able to provide a downward acting compression force against the soft goods. In further aspects of this invention, the compression force is adjustable; and the conveyors are powered by the slitting wheel motor.
In a still further embodiment of the invention, an apparatus for feeding and slitting compressible soft goods has a stationary table for supporting the soft goods. A rail is disposed above, and extends across a width of, the stationary table. First and second slitter and feed mechanisms are mounted on the rail adjacent side edges of the table. The slitter and feed mechanisms are movable across the width of the table. A first actuator is mounted on the rail and has a reciprocable drive shaft pivotally connected to the first slitter and feed mechanism, and a second actuator is mounted on the rail and has a reciprocable drive shaft pivotally connected to the second slitter and feed mechanism. Thus, the separation of the slitter and feed mechanisms can be controlled to trim different widths of soft goods.
These and other objects and advantages of the present invention will become more readily apparent during the following detailed description taken in conjunction with the drawings herein.